A tale of 2 cancers co existing in 1 host.

I recently encountered a particularly challenging case that underscores the complexities of cancer diagnosis and treatment. Its about a tale of cancers coexisting in 1 host.

The patient, a 70-year-old man, initially presented with persistent back pain. An MRI revealed spinal metastases, prompting further investigation to identify the primary cancer source.

The patient’s PSA level was alarmingly high at over 700, leading to a diagnosis of stage 4 prostate cancer. A PSMA PET scan showed a primary prostate cancer with metastases to the bones and lymph nodes which is a common presentation. Treatment began with Zoladex, and after three months, his PSA levels decreased. Despite this, his back pain worsened, necessitating a referral for radiotherapy to alleviate his discomfort.

Upon reviewing the patient's case, I noticed discrepancies. His CEA levels were elevated, and the severity of his back pain did not align with the findings on the PSMA PET scan. To gain a clearer understanding, I opted for a FDG PET scan, which revealed discordant results compared to the initial PSMA PET scan. This prompted me to perform a biopsy of his spine, which surprisingly indicated an EGFR exon 19 mutation, revealing a concurrent diagnosis of lung cancer.

PSMA PET on the left and FDG PET on the right (discordant)

Spine lesion on PSMA PET (without uptake) on the left and spine lesion on FDG PET (with uptake) on the right

This patient was simultaneously battling two stage 4 cancers: prostate and lung. To address both conditions, I started him on Afatinib for the lung cancer while continuing the Zoladex for prostate cancer. Remarkably, two months later, his CEA and PSA levels showed improvement.

Managing two stage 4 cancers is rare, and initiating dual targeted therapies is even more uncommon. After discussing the situation with the patient, we decided to pursue a dual-targeted therapy approach: Afatinib for the lung cancer and Apalutamide for the prostate cancer, given its metastatic castrate-sensitive status.

Six months into this regimen, the patient is showing a positive response. Although he experiences grade 2 toxicities from the dual therapy, his overall quality of life remains good. This case highlights the importance of thorough investigation and tailored treatment plans in managing complex cancer cases.

Left (6 months post dual targeted therapy), right (pre dual targeted therapy)